A modern arrow comprises several components, some of which are designed to be assembled and/or replaced by an archer with the intent of facilitating interchangeability or repair in a simple home workshop environment or, if need arise, in the field. One group of such components are 1) the arrow tip, 2) the arrow shaft and 3) the threaded insert that connects the arrow tip to the arrow shaft.
To achieve true flight, the longitudinal axis of the tip should be collinear with the longitudinal axis of the arrow shaft. Any deviation of the tip away from the longitudinal axis of the shaft must be minimized to prevent inadvertent arrow flight. An arrow is generally constructed having a hollow cylindrical inner diameter. A threaded insert is placed within the hollow center of the arrow shaft such that a face of the threaded insert is perpendicularly aligned to the longitudinal axis of the arrow shaft. The arrow tip is normally threaded onto or into the threaded insert and abuts the face of the threaded insert. A drawback of the conventional method of installing the threaded insert to the arrow shaft is that assembly is often done by the archer and includes an adhesive to join the threaded insert to the arrow shaft. The following situations are known to cause alignment problems: 1) the face of the threaded insert not being perpendicularly aligned to the centerline of the insert, 2) the combined misalignment of the threaded insert and arrow shaft joint, 3) the build-up of excessive amounts of adhesive between the threaded insert and the arrow shaft forcing the threaded insert face out of perpendicular alignment with the longitudinal axis of the arrow shaft. When any of these situations occur, the tip when threaded into or onto the threaded insert will abut the misaligned insert face forcing the tip out of collinear alignment with the longitudinal axis of the arrow shaft.
The adhesive used to join the threaded insert to the arrow shaft is normally an epoxy or a hot-melt glue. When applying the adhesive, an archer who is performing this operation will not have the necessary tools to ensure that the runout between the threaded insert and the arrow shaft is minimized when the threaded insert is assembled. A small error in runout (i.e., misalignment) on the mounting surface is greatly magnified at the arrow tip. The minimum magnification ratio of this error is normally about 10:1. An exemplary 0.025 mm (0.001 inch) error in runout will therefore magnify to a 0.25 mm (0.01 inch) misalignment of the arrow tip from the desired longitudinal axis of the arrow shaft.
A further drawback exists if the alignment of the machined or squared end of the arrow shaft is not perpendicular with the longitudinal axis of the arrow shaft. An archer when joining the threaded insert to the arrow shaft normally has no means of truing the end of the arrow shaft before insertion of the threaded insert. This error is further magnified when the threaded insert is joined with the arrow shaft. Most arrow shafts are now constructed of aluminum or a carbon fiber composite material. At the present time, there is a need for an effective means to machine, clean, or de-burr the end of an arrow shaft, and, when the shaft material is a carbon fiber composite, an effective means that minimizes splintering of the arrow shaft.